History

As always, the key components of the medical history focus on the “when,” “where,” and “how.” The time of injury is critically important, especially when dealing with devascularizing injuries. Bone, integument, and muscle have, in that order, decreasing tolerances to ischemia, with muscle being able to survive only 4 to 6 h of it, even with the normal tissue cooling that occurs after ischemia. In addition, the longer the duration from the time of injury, the greater the risk for infection, with delays greater than 6 to 12 h precluding primary closure or coverage. If ischemia is present, the temperature of the tissue during the ischemic period is critical inasmuch as extremity tissues devoid of muscle can be successfully revascularized after 12 to 24 h if kept cool. In fact, successful digit replantation has been reported at 94 h.

The “where” of an injury is also important. Farming injuries, for example, tend to be highly contaminated and require more than the usual amount of aggressive debridement, which often precludes primary closure. The presence of caustic industrial chemicals or other contaminated substances can also affect treatment choices. The social and economic aspects of the injury environment must likewise be weighed when planning treatment. A patient living in an area remote from an appropriate medical facility may not be able to follow through with the complex rehabilitation program required for a highly technical reconstruction and may be better served with a more straightforward reconstructive option.

Finally, the “how,” or mechanism of injury, can help reveal the force of it and the extent of tissue necrosis or zone-of-injury to anticipate and address during treatment. Sharps injuries tend to involve a limited zone of tissue and are therefore easier to manage, unless the injury is tangential in nature. High-velocity, high-pressure crushing or avulsion injuries have a much broader injury zone and require a modified approach to treatment, which needs to consist of more extensive debridement, thorough evaluation of adjacent tissues, removal of foreign bodies, and assessment for and treatment of compartment syndrome.

The patient’s overall health and comorbid conditions must be carefully evaluated in planning any type of complex or lengthy reconstructive procedure. The patient’s age and the presence of cardiovascular disease, pulmonary disease, bleeding tendencies, or diabetes can greatly increase the risk for perioperative complications or even mortality; any of these should cause the surgeon to consider simplifying the reconstruction method or at least modifying perioperative treatment plans. Smoking or the use of other vasoactive drugs, such as cocaine, is generally a contraindication to any type of complex microvascular reconstruction.

Perhaps the most important aspect of obtaining a history is determining the patient’s functional needs and goals. The age, occupation, socioeconomic environment, and social support systems should all be considered when formulating a treatment plan. Both the risks that the patient is willing to accept and the costs in terms of financial, emotional, and time must be considered. Willingness to endure a protracted reconstructive course and a patient’s ability to follow through with the necessary hand therapy are important issues. A self-employed farmer, without workers’ compensation insurance, will probably be interested in reconstructive options that offer an expeditious return to work and provide durable function suited for heavy work without multiple complex reconstructive procedures.

An office worker or technology professional may have very different goals and might be more willing and economically able to undergo multiple reconstructive procedures to restore optimal digit function to allow fine manipulation, keyboarding, and other such tasks. Again, the hand surgeon must make decisions based on personal knowledge and experience to try to predict the patient’s ultimate function with the available reconstructive options so that the most appropriate option can be selected for that particular patient. Both the patient and the patient’s family must be involved in this discussion, although this is often difficult to do when the patient has just suffered a mangling injury, so surgeons frequently must use their best judgment at the time by taking into account all the known variables.

Examination

Because examination of a patient with a severely mangled extremity injury that is wrapped in blood-soaked towels or bandages is often difficult in the emergency department, definitive evaluation often must wait until the operating room. Nevertheless, assessment of injuries to major structures, in particular vascular status, is essential in determining the urgency of definitive treatment and also important in the ability to discuss treatment options and prognosis with the patient and family. Usually, a general assessment of vascular status, sensibility, and muscle–tendon unit function, as well as radiographic evaluation, can and should be done in the emergency department. Preliminary evaluation will also allow adequate preparation of the operating room: microsurgical equipment and supplies, implants and fixation devices, traction and radiographic devices, and other necessities.

The most important system to evaluate is the vascular system of the extremity. Compromised vascularity of the digit or extremity, depending on the duration of devascularization, can dictate whether the digit or limb can be salvaged, whether fasciotomy is required, and the urgency of initiating treatment. Assessment of vascular status is best performed by direct inspection of the patient’s affected tissues and comparison to adjacent or similar well-vascularized tissues. Although nail bed capillary refill is traditionally considered a good indicator of peripheral perfusion, it is in fact a very unreliable indicator of perfusion. A completely devascularized digit can have what appears to be intact capillary refill beneath the nail bed when in actuality stagnant blood is merely being pushed to the sides with compression and then moving back to the center with release of pressure on the nail bed.

A far more reliable area to assess digit perfusion is the dorsal paronychial tissue on the sides of the nail, which should be pink and spongy and have good turgor, compressing with pressure and refilling with release ( Figure 43.4 ). A pink color that returns within 1 to 2 s after the application and release of pressure indicates healthy tissue, whereas a pale color without capillary refill or turgor can represent arterial insufficiency. A dusky color with exceptionally brisk refill can be indicative of venous congestion. Probably the most reliable clinical indicator of tissue vascularity is the color of the blood that oozes from the tissue after sticking it with a needle or scalpel. Bright pink oozing reflects healthy tissue, whereas dark purplish oozing reflects compromised perfusion if it is sluggish or venous insufficiency if it is profuse. Obviously, this should not be performed on the sensate tissue of an awake patient but is often useful in an anesthetized one.

A completely devascularized digit can have what appears to be intact capillary refill beneath the nail bed when in fact stagnant blood is merely being pushed to the sides with compression (A) and then moves back to the center with release of pressure on the nail bed (B) . A far more reliable area to assess digit perfusion is the dorsal paronychial tissue on the sides of the nail, which should be pink and spongy and have good turgor, compressing with pressure and refilling with release (long finger, arrow ), whereas a devascularized digit’s paronychial tissue (C) will be pale and flat, without turgor (ring finger, arrow ).

For assessing the status of the major vessels of the upper extremity and even the digital vessels, a handheld Doppler probe is very useful. The standard Allen test, performed by compressing either the radial or the ulnar artery and listening for a signal over the palmar arch or the most distant digital artery, can help determine whether either the radial or ulnar artery has antegrade flow and whether the palmar arch is intact. Angiography has a minimal role in mangling injuries of the forearm, hand, or fingers. In any mangling or crushing injury, a high index of suspicion for compartment syndrome must be maintained.

The diagnosis and treatment of compartment syndrome are covered in Chapter 51 , but it is worth reinforcing the importance of recognizing the intense pain of it and, in particular, pain with passive stretch of muscle–tendon units. When suspected, the diagnosis is best confirmed by direct measurement of pressure in the muscle compartment, usually with a handheld device specifically designed for this purpose. The presence of compartment syndrome and attendant tissue ischemia warrants emergency decompression in the operating room.

Although obvious deformity, crepitus, or tenderness on examination can suggest underlying skeletal injury, evaluation of the skeletal system is generally performed radiographically. In most instances, standard plain radiographs are sufficient if care is taken, whenever possible, to ensure that emergency splints or traction devices do not obscure the underlying bones or joints. Sometimes, additional views are needed, including oblique views to assess articular congruity or stress views to evaluate ligament injury (e.g., a clenched fist view to evaluate intercarpal ligamentous integrity). In questionable cases, comparison views with the contralateral extremity, if uninjured, may be necessary.

With most mangling injuries, advanced imaging techniques, such as computed tomography (CT) or magnetic resonance imaging (MRI), are rarely indicated, although at times if the patient is stable, CT scanning of suspected carpal injuries or intraarticular displacement can be useful. If amputated parts are involved and replantation is contemplated, radiographs of the amputated parts should be obtained. Moreover, as always, the joint proximal and the joint distal to the area of injury must be evaluated ( Figure 43.5 ). Ligamentous injuries can be identified by tenderness to palpation or to stress. Stability with the application of stress should also be reevaluated under anesthesia to remove any confounding effect of involuntary muscular splinting.

The importance of obtaining radiographs that include the entire extremity, including a joint above and below the obvious injury, is illustrated in this case of a 22-year-old man who sustained multiple injuries resulting from a motor vehicle accident. A, Complaints of wrist pain prompted the radiographs. There is an ulnar styloid fracture and subluxation of the distal radioulnar joint (DRUJ). B, Elbow radiographs showed no obvious pathology. C, The DRUJ was transfixed with Kirschner wires. D, Within 3 weeks the Kirschner wires bent. E, The fixation wires were removed, full-length forearm radiographs were obtained, and the culprit—a Galeazzi fracture—was identified. F, Restoration of the radius and soft tissue reconstruction of the DRUJ resulted in 80 degrees of pronation and 60 degrees of supination.

Evaluation of injury to muscle–tendon units is best performed by having the patient actively flex and extend the digits and wrist. In the presence of pain, and especially with underlying skeletal injury, this examination can be difficult to interpret. For the individual digits, noting aberrations in the normal resting cascade can indicate injury to the underlying flexor muscle–tendon unit. This simple observation can be performed even in a comatose patient, as can evaluation of tendon function by passively flexing and extending the wrist and observing the normal cascade of digit flexion with wrist extension and digit extension with wrist flexion ( Figure 43.6 ). In the end, however, with most mangling injuries, definitive evaluation of tendon injury must wait for careful examination in the operating room.

Evaluation of tendon function by passively extending (A) and flexing (B) the wrist while observing the normal cascade of digit flexion with wrist extension and digit extension with wrist flexion.

Nerve injury is evaluated by examining both motor and sensory function. The motor function of the median, radial, and ulnar nerves is assessed by testing both extrinsic and intrinsic muscle function. Three simple maneuvers test motor integrity: (1) resistance to palmar abduction of the thumb reflects median nerve-innervated abductor pollicis brevis function, (2) resistance to flexion of the metacarpophalangeal (MP) joint of the small finger reflects ulnar nerve–innervated flexor digiti quinti function, and (3) resistance to extension of the MP joint of the index finger reflects radial nerve–innervated extensor digitorum communis and extensor indicis proprius function.

Accurate sensory examination is much more difficult, especially in patients with severe injury. By using a light touch and, if questionable, pinprick testing, a reasonable assessment can nevertheless be obtained. If the injury is in the palm or digits, specific attention should be directed to digital nerve function, whereas if the injury is more proximal, attention should be directed to independent areas of sensory function, such as the volar aspect of the index or middle finger, for median nerve function, the volar aspect of the small finger for ulnar nerve function, and the dorsum of the first web space for radial nerve function.

With sharps or penetrating injuries, if you “think the nerve is probably OK,” it usually is not. Equivocal results on examination generally indicate an underlying injury that warrants exploration, whereas normal sensory results, with the patient not looking, usually indicate an intact nerve. With blunt or blast injuries, however, nerve contusion and neurapraxia with the nerve in continuity are not uncommon. The threshold of suspicion for exploration of nerves in patients with sharps or penetrating injuries should therefore be much lower than with blunt or blast injuries.

Laboratory studies should be obtained at this time, including a complete blood count with platelets, electrolytes, and any other tests appropriate to the clinical situation (e.g., blood gas analysis, toxicology screen, amylase, and others). In addition, if there has been significant bleeding or considerable bleeding is anticipated during surgery, blood for typing and cross-matching should be obtained at this time.

Amputation/Skeletal Contribution

According to the guidelines of the American Medical Association (AMA) for evaluation of permanent impairment, the thumb accounts for 40% of hand function, the index and middle fingers for 20% each, and the ring and small fingers for 10% each. These contributions should be kept in mind when deciding between reconstruction/replantation versus amputation. In the case of mangling injuries, however, these relative contributions do not always apply. For example, with loss of the three central digits, the small finger effectively assumes 50% of hand function.

As discussed previously, surgeons must use their knowledge, experience, and best judgment in an effort to predict a patient’s ultimate function with amputation versus reconstruction and with the various reconstructive options. The factors of patient age, health, drug or nicotine use, occupation, and willingness and ability to undergo complex or multistaged reconstructive procedures and rehabilitation must be taken into account. The topics of amputation, replantation, and thumb reconstruction are covered elsewhere in this text, and the reader is referred to these sections for more detailed coverage of the topics.

The thumb is, of course, the most important digit to preserve or reconstruct. The issues related to thumb amputation are discussed in Chapter 48 and vary depending on the level of injury. Interphalangeal (IP) joint motion and the distal phalanx are of relatively lower importance to preserve than multiplanar carpometacarpal (CMC) motion and, to a lesser extent, MP motion. The ability to bring the thumb out of the plane of the hand and into a position of opposition is a key function that must be restored. If the thumb cannot be preserved, consideration should be given to primary pollicization ( Case Study 43.2 ).

Case Study 43.2

A 50-year-old male suffered a crush/avulsion injury from industrial machinery to his thumb, index, and middle finger. Initial debridement and index ray amputation were performed ( eFigure 43.3 ).

Crush/avulsion injury to thumb, index, and middle finger. A, B, Radiographs. C, D, Clinical photos 48 h after injury (with one debridement). E, F, Injury following second debridement.

What is the preferred coverage method for this wound (keeping in mind that a toe transfer may be needed for thumb reconstruction)?

• 
  
  
  
  
  
  • a.
    

    Pedicled reversed radial forearm fasciocutaneous flap

    
    
  • b.
    

    Groin flap

    
    
  • c.
    

    Free radial forearm flap

    
    
  • d.
    

    Split thickness skin graft

  
  
  
  
• 
  

  Answer: (b) Groin flap

Rationale: A split thickness skin graft is not appropriate coverage for the exposed thumb skeleton. While a pedicled or free-radial forearm flap would provide coverage, both of these options would alter the radial artery which is the preferred recipient artery for a toe transfer. Therefore, a groin flap is the preferred coverage type.

See postoperative images in eFigure 43.4 .

Crush/avulsion injury to thumb, index, and middle finger treated with groin flap. A, Following groin flap division. B, C, Radiographs. D, E, Appearance following multiple groin flap debulkings. F, G, Great toe pulp transfer to restore sensibility. H, Toe pulp flap inset. I, J, Appearance following first web contracture release.

The index finger is also important to preserve because of its independent profundus flexion and ability to abduct for precision pinch functions. Without good function and sensibility of the proximal interphalangeal (PIP) joint, however, the index finger is often bypassed in favor of the middle finger because it can be more of a hindrance than help and ray amputation can often improve function by opening the first web space. Amputation at or proximal to the PIP level leaves only the intrinsics for flexion, which is then limited to about 45 degrees. The long and ring fingers are important primarily for grip and grasp functions, although either can take over pinch functions for the radial digits if they are lost. Solitary loss of the ring finger probably results in the least associated functional deficit of all the digits. The small finger, even though it has the least flexion strength, is actually quite important in hand function in that it defines hand width for grip functions, use of tools, and other applications. An important component of this function is the significant CMC motion of the small finger that comes into play with terminal grip.

With amputation at the proximal aspect of the middle phalanx (P2), PIP, or especially the MP level, ray amputation also needs to be considered. Although ray amputation is usually aesthetically preferable to a partial finger amputation, function can suffer. For the index finger, power grip, key pinch, and supination strength are diminished approximately 20%, and pronation strength approximately 50%. There is also a fairly high rate of dysesthesia after ray amputation, thus further arguing against routine ray amputation.

Loss of an isolated digit other than the thumb rarely results in significant compromise of hand function, and as Brown has noted, patient motivation is more important in regaining function than the actual digits lost. Loss of multiple digits, however, is common with mangling injuries and frequently results in significant functional deficits. Maintaining or reconstructing at least the thumb and one opposing digit is a minimum requirement for any type of pinch or grasp. Retaining or reconstructing an additional adjacent digit can nevertheless add significant function by providing lateral stability to the radial digit for power pinch and can allow three-jaw chuck pinch.

Joints

The choice of whether to salvage or fuse a joint is another decision that is often difficult. It is best made by assessing the potential loss of function from a given fusion or set of fusions versus the risk for limited motion, pain, instability, or late arthrosis with reconstruction. Whenever anatomic articular congruity and ligamentous stability can be restored, reconstruction is usually worthwhile. When it cannot be achieved, the potential loss of function needs to be assessed. In general, distal interphalangeal (DIP) fusions of the digits or IP fusion of the thumb is tolerated well with limited loss of function. PIP joint motion is much more important to preserve. Littler and colleagues described the PIP joint as the “functional locus of finger function.”

Not only are fingers with fused PIP joints of little use for grip or grasp, but also they frequently get in the way and are easily injured because they do not follow the normal arc of the other fingers. An additional problem, though less so with the index finger, is the quadriga effect, which can occur when profundus excursion is impaired with arthrodesis. Although delayed arthroplasty can be considered, in the presence of combined injuries involving the joint, nerve, and soft tissue, if the PIP joint cannot be primarily reconstructed, serious consideration should be given to amputation, especially of the ulnar two digits.

The MP joint is perhaps the most important joint in terms of function for the index through small fingers in that it contributes 77% of the total arc of finger flexion. Most activities, however, do not require the full arc of MP motion, and in fact as little as 35 degrees of motion can be acceptable if that arc is within the key functional range and the joint is stable. To that end, stable but markedly limited MP motion, even arthrodesis, is far superior to an unstable, painful MP joint ( Figure 43.8 ).

A, Five-digit amputation in an 18-year-old man resulting from a saw accident. B, Treatment consisted of primary arthrodesis of the finger metacarpophalangeal joints and replantation of the index, middle, ring, and small fingers. The thumb could not be replanted. Six months after injury, the thumb was reconstructed with a second toe-to-hand transfer. Hand motion is demonstrated a year after the injury.

The decision to perform partial or total wrist fusion is seldom made in the acute setting unless there is extensive, nonreconstructible loss of articular surface. Usually, this decision is deferred until late function and pain can be better assessed, at which time elective arthroplasty or arthrodesis can be performed. Studies have shown that as little as 5 to 10 degrees of flexion and 30 to 35 degrees of extension are needed for most activities of daily living. When wrist-level amputation is required, preservation of some wrist motion can be incorporated into mechanical prostheses, and preservation of an intact distal radioulnar joint can significantly improve pronation and supination under loading conditions. The functional benefit of preserving the distal radioulnar joint, although attractive in theory, has never been proved in practice.

Tendons

Preservation and reconstruction of skeletal length and joint motion are of little use without a mobile muscle–tendon unit to move it. Because of its complex balanced “shroud” mechanism and limited excursion, the extensor tendon mechanism, especially over the digits, is susceptible to minor changes in length with repair, as well as adhesion formation and underlying skeletal injury. Intrinsic function is also easily compromised in mangling injuries, especially crush and blast injuries with multiple metacarpal fractures.

Fibrosis and contracture leading to significant disability are common. Because of the overlap in function and transmission through the juncturae tendineae, injuries to the extrinsic extensor tendon tend to be more forgiving, especially if a limited number are involved. Although not ideal, complete loss of the extrinsic extensors with associated reconstruction of dorsal soft tissue coverage and the presence of intact intrinsics is tolerated quite well. In this setting, the ensuing deep cicatrix formation allows adequate MP flexion and extension through scar tenodesis. This, combined with intact IP function, results in good overall hand function.

Preserving or reconstructing flexor tendon function in a mangled hand is obviously important but frequently difficult to achieve. It is often difficult to restore independent superficialis and profundus function, and the pulley systems are frequently ruptured. To prevent bowstringing, the A2 and A4 pulleys must be preserved or reconstructed. Given the limited tolerances within the flexor pulley system, it is sometimes best to repair only one tendon, usually the profundus tendon, especially if repairing both tendons would lead to adhesions and limited excursion. Two other complications of profundus injury must also be kept in mind and avoided: lumbrical-plus deformity and quadriga.

Lumbrical-plus deformity occurs when a cut and unrepaired profundus retracts, thereby increasing tension on the lumbrical that results in paradoxical extension with digit flexion. This is avoided by either repairing the profundus or, as with amputations, suturing it without tension to the flexor sheath. Quadriga primarily affects the middle through small fingers and is a result of these tendons arising from a common muscle belly. If one profundus becomes adherent in a lengthened position or is repaired with significant shortening, it can prevent full flexion of the remaining digits.

Soft Tissue Coverage and Nerves

Providing durable, stable, pliable soft tissue coverage, with at least a protective sensation in the areas of functional contact, has long been recognized to be the most important factor in determining outcome after mangling injuries. Stability of soft tissue coverage is often overlooked in the quest to provide bulk, padding, and durability; it is especially important on the volar aspect of the hand and digits. A bulky, mobile flap subject to shear with a tangential load leads to poor grip function. One can imagine how difficult the simplest of tasks would be if a small water balloon were strapped to one’s palm. For this reason, surgeons favor fascia flaps or thin muscle flaps that are skin grafted, as opposed to thick fasciocutaneous or musculocutaneous flaps, especially on potentially friction-dependent, load-bearing surfaces.

Restoring protective sensation (i.e., 7–15-mm two-point discrimination) to the palmar weight-bearing surfaces of the hand is critical. According to the AMA’s Guides to the Evaluation of Permanent Impairment , greater than 15-mm two-point discrimination is considered functionally insensate. Nerve repair, whether primary or delayed, is an essential component in reconstruction of a mangled hand.

Emergency Treatment

By far the most important aspect of treating a mangling extremity injury is to evaluate the patient and treat other life-threatening injuries before proceeding to evaluation and treatment of the extremity injury. Once the patient has been stabilized and attention can safely be turned to the extremity, the most emergent aspect of treatment is controlling ongoing hemorrhage. This is best done by applying direct pressure to the bleeding area long enough to allow the effects of reflex vasoconstriction and thrombus formation to effectively control the bleeding. Sometimes a compressive dressing held on by an elastic bandage is necessary. In the rare circumstances when direct pressure is ineffective, it may be necessary to temporarily inflate a proximal blood pressure cuff as a tourniquet until the area of bleeding can be identified and controlled.

It must be kept in mind, however, that tissue distal to the injury may have already been subjected to a period of ischemia and that further complete ischemia will compromise the ability to salvage the limb. Because of the many critical structures running through the extremity, in particular, nerves and arteries, it is important to never blindly clamp bleeding areas and to use clamps only on a specific, well-visualized vessel while being careful to not include any adjacent nerve.

It has been shown that in cases of severe mangling and devascularizing injuries, revascularization before skeletal reconstruction reduces morbidity. If either the brachial artery or both the radial and ulnar arteries are transected or thrombosed, and if extensive skeletal stabilization is going to be required, especially if ischemia has already been present for some time, a vascular shunt should be placed as an initial step. This should be done before operative debridement or skeletal fixation to reperfuse the tissues and remove the time pressure so that meticulous debridement and appropriate skeletal fixation and tendon repair can be performed before definitive revascularization.

A standard carotid vascular shunt usually works very well for the brachial, radial, or ulnar arteries. Before inserting the shunt, any thrombus or debris should be removed from the proximal and distal segments with a No. 2 Fogarty catheter to prevent distal embolization after restoration of flow ( Figure 43.9 ). Once the arterial shunt has been connected, it is recommended that the extremity be allowed to bleed so that toxic metabolites do not enter the circulation. In the case of critical ischemia of the upper extremity, 200 cc of bleeding is sufficient to clear the waste products.

This 24-year-old man sustained a combined complex injury resulting from a rollover motor vehicle crash. In addition to his open fractures were forearm muscle and skin avulsions and transection of the brachial artery. This accident occurred in a rural area, 6 h from the nearest trauma center. The surgeon removed gross debris, reconstructed the artery with a vascular shunt (A) , and then transported the patient to our facility. Further treatment consisted of debridement, skeletal fixation, revascularization with vein grafts, and soft tissue reconstruction with a free rectus abdominis muscle flap and split-thickness skin grafts. B, These photographs were taken a year after the injury. Forearm rotation is limited to 90 degrees, shared equally by pronation and supination.

As noted earlier, cooling the tissue is the most effective way to prolong the length of time that tissue can be ischemic yet still remain viable. When tissue is amputated, including digits, limbs, or other potentially revascularizable tissue, it should be wrapped in saline-soaked gauze, put in a plastic bag or container, and placed on ice until it can be revascularized. All intact skin bridges should be left intact. There are often critical draining veins within the skin bridge that can provide adequate venous drainage, thereby obviating the need for venous reconstruction at the time of revascularization. In this case, the ischemic digit or limb should simply be wrapped with moist gauze or a moist towel if the patient is not suffering from hypothermia.

Gross skeletal deformity caused by either fracture or dislocation compromises distal circulation and should be reduced, whenever possible. If any flaps of tissue have been traumatically elevated, they should be gently placed back into anatomic position without any tension or kinking to optimize circulation. It is, of course, important to document the results of motor and sensory examination before administering local, regional, or general anesthesia.

With any open wound, the patient’s tetanus prophylaxis status should be reviewed and the appropriate prophylaxis given, according to the standard guidelines ( Table 43.1 ). Appropriate intravenous antibiotic prophylaxis should be started at this time. In most instances, a first-generation cephalosporin is adequate because the most common infective organism with open hand injuries is Staphylococcus aureus . With agricultural injuries or those that occur at other highly contaminated areas, additional gram-negative coverage should be provided (i.e., an aminoglycoside).

Operative Treatment

Debridement/Wound Excision

The initial debridement is perhaps the single most important step that determines the functional outcome of mangling injuries. Performing it properly requires experience and judgment. It should therefore not be left to a junior resident to perform. If the initial debridement is inadequate and nonviable tissue is left behind, the result will be infection, further tissue loss, and potential loss of limb or life that might otherwise be prevented. As Pasteur described and as was reinforced by the work of Dellinger and colleagues: “It is the environment, not the bacteria, that determine whether a wound becomes infected.” Because there is little in the hand and upper extremity that is not functionally important, some argue for conservative initial debridement so that marginal tissue can “declare itself” over time. We strongly disagree with this approach.

Marginally viable tissue leads to further toxic insult to adjacent tissues, as well as systemic complications. Instead, we favor aggressive debridement of marginally vascularized tissue, especially muscle. The only two exceptions to this approach are (1) if revascularization is going to be performed, final debridement should await definitive revascularization; and (2) in the case of pure skin flaps that are critical for coverage of vital structures, the risk for sepsis by waiting 24 to 48 h for demarcation of viability is small. Nevertheless, if skin does not bleed or oozes only dark blood at the time of initial surgery, it should be debrided. The concept of debridement in the face of mangling injuries should therefore actually be thought of as “wound excision” to create a healthy soft tissue bed for reconstruction.

Unless prolonged muscle ischemia has already occurred, initial debridement is best performed under tourniquet control. This allows safe visualization and preservation of critical structures, specifically major nerves and vessels. Using loupe magnification, all foreign material should be carefully removed, along with clearly devitalized skin, subcutaneous tissue, and muscle. Frayed tendon should be debrided of only loose strands, with any potentially structural portions left intact. Unless clearly destroyed, nerves should be left intact and any foreign material carefully removed. If a major muscle is debrided, one should tag the motor nerve to potentially use later for functional free muscle transfer. The ends of transected major nerves should be tagged with sutures if primary repair is possible or with metal vascular clips if delayed nerve grafting will be necessary; this will help in later identification of the nerve ends, either directly or radiographically.

Similarly, the transected ends of major vessels (e.g., the radial, ulnar, anterior interosseous, palmar, or digital arteries) to be repaired should be clamped with spring-loaded microvascular clamps. Smaller branches should be ligated with either suture ties or vascular clips, which we prefer because they are less likely to become a nidus for infection. Nonstructural bone fragments that are not attached to soft tissue should be saved for keying reduction. Attached and potentially viable fragments should be saved, along with structurally important fragments. The remaining bone should undergo curettage to remove contamination and allow anatomic reduction. The wounds should then be irrigated with a gravity-assisted irrigation system if large or with bulb/syringe irrigation if small. The mechanical debridement achieved by scrubbing with a sterile gauze sponge during irrigation is very important.

At this point, the tourniquet should be released and areas of significant bleeding either cauterized or ligated with vascular clips. Any tissues, particularly muscle, that are not pink and bleeding should be debrided down to healthy bleeding tissue. At times it is necessary to reinflate the tourniquet briefly for further debridement. We have not found tissue taken for culture at the time of initial debridement to be of much clinical value. If the wound is heavily contaminated, or if there are remaining critical areas where viability is not certain, planning for repeat operating room debridement in 24 to 36 h is in order, especially with severe crush injuries.

The debridement phase is when decisions regarding replantation, amputation, partial amputation, or reconstruction must be made, again by looking into the “crystal ball” to predict ultimate function with the various options and relying on the principles described previously for guidance. If amputated tissues have been recovered and on initial inspection are thought to not be appropriate for replantation, they should nevertheless be saved because they could be useful as “spare parts” later in the operation—either as vascularized or nonvascularized grafts: bone, tendon, nerve, or skin. The technical details of various types of amputations are described in Chapter 50 .

For the digits, if less than a functional amount of the proximal phalanx remains, we will often perform a ray resection or, in the case of the middle finger, an index-to-middle finger transposition at the time of the initial operation. If the remaining ray will not contribute to function, removal of it can often help in achieving primary soft tissue closure; the skeletal components should be removed, the vascularized soft tissue portions saved, and a “fillet flap” created. This is also the point to pause and plan the reconstruction, both the steps to be performed in the current operation and the type of future operations that may be required. After debridement, reconstruction should then proceed beginning with skeletal reconstruction and working from the base up to the skin.

Critical Points

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